U.S. Trade Representative Kirk to step down in late February

U.S. Trade Representative Ron Kirk on Tuesday said he was stepping down as the top U.S. trade official, effective in late February. He leaves after a turbulent four years for the global economy that made progress difficult on the trade front.

"It has been no less than my greatest professional privilege to serve President Barack Obama alongside the dedicated professionals of USTR," Kirk said in a statement that gave no details of his future plans or replacement.

The former Dallas mayor and early Obama supporter oversaw congressional approval of free trade agreements with South Korea, Panama and Colombia left over from the previous administration and the completion of negotiations on Russia's entry into the World Trade Organization. (Reporting By Doug Palmer; Editing by Sandra Maler)